This section provides background information related to the present disclosure which is not necessarily prior art.
Fuel injections systems configured to supply high-pressure fuel from a fuel pump to a set of fuel injectors are well-known. In such systems, a fuel rail assembly consists of common rail and the injector feed lines supplying the fuel from the pump to the injectors and functions as a high-pressure accumulator to stabilize the fuel pressure. The dynamics of this system are such that pressure fluctuations in the fuel rail assembly during all phases of operation may excite certain hydrodynamic and structural resonances. These resonant frequencies depend on the geometry of the fuel rail assembly and the bulk moduli of the rail material and the fuel, which in turn depend on the temperature of these components.
The pressure fluctuations result from a plurality of hydrodynamic inputs in the system including pressure pulses generated by the high-pressure pump, pressure pulses induced by opening and closing of the injectors, and pressure pulses resulting from fluid waves present in the fuel rail and injector lines. The frequency of these pressure pulses vary over the operating range of the engine, and thus can drive multiple resonances of the fuel rail assembly depending on the load and operating conditions of the engine. The hydro-mechanical interaction between the pressure waves and the fuel rail assembly when driven at resonant frequencies can generate unwanted noise and vibration which propagates from the vehicle engine. In addition, extreme excitation of the fuel rail assembly may accelerate structural fatigue in the components of the assembly, thereby affecting the durability of the fuel injection system.
Accordingly, there is a need to develop a means for controlling fuel pressure to provide a stable fuel pressure and attenuate dynamic pressure waves within the system over the entire range of operation.